1. Field of the Invention
The present invention relates to an ultrasonic transducer, and more particularly, to an ultrasonic transducer that is capable of sensing an obstacle at the periphery of a vehicle.
2. Discussion of Related Art
Ultrasonic transducers that are used in vehicles, according to the related art, are mounted in bumpers of vehicles and used as obstacle sensors.
In ultrasonic transducers used for this purpose, if a transmission and reception range of ultrasonic waves in a horizontal installation direction is extremely narrow, blind spots are formed in the range of detection. Also, if the transmission and reception range of the ultrasonic waves in a vertical direction is extremely wide, waves reflected from the ground become noise. Thus, horizontal rather than vertical directivity is required.
In order to obtain such directivity, directivity has been generally improved by forming slits that are symmetrical to sides of a housing of an ultrasonic transducer.
However, in the case of such a configuration, foreign substances are introduced from the outside through slits formed in sides of the housing, and the introduced foreign substances accumulate on the periphery of a piezoelectric resonator, which lowers performance of the ultrasonic transducer. Also, due to complexity of the structure of the housing, processing including forging and cutting needs to be generally performed on the housing formed of an aluminum material such that manufacturing cost increases.